I came home late last night and had not shut the coop up yet. I knew something was very wrong because a large group of my 11 week olds were in the middle of the field near our house safety light. They were about 80 foot from the coop. I headed to the coop and only one chicken was in there but she was fine. The others were following me around with my flashlight so I started sticking them in the coop. Coop door is 10.5 inches by 12 inches. 6, 11 week old chicks were missing. They free range all day and I do not have a run surrounding my coop. I locked the remaining 30 up and got my lab from the house. He is a trained bird dog as well as being scent trained for several kinds of wildlife and is just generally nosy so I can send him on a just about any kind of animal trail. He pointed in the thick grass about 60 foot from the coop (opposite direction from house and from 1st group of chickens). In the grass I found my live and apparently unharmed EE cockerel. He is one of the better flyers. Walking further back my lab picked up a dead BCMarans cockerel and brought it to me. It was about 20 foot further than the EE so 80 foot from the coop. He was already stiff but only had evidence of predation on his neck in the form of small bloody scratches. No missing feathers. My lab followed a trail from here down the fence line to the apparent crossing point. Here I found a dead EE still warm. Head was gone, 1 leg gone. 1 leg present but eaten on. Entrails eaten on. It was not plucked and I only found a single loose feather here and there around the coop and field. My 90 lb lab barely fit under the fence crossing point even with me pulling up the bottom of the fence. Every predator here would be smaller than him though so that does not tell you much. In the next field, my lab went off still on the trail. I walked along after him looking for more signs. He came back after a minuet with my White New Jersey Giant pullet stiff and cold. Her head and neck were gone and her gizzard was hanging out. Most of her internal organs were gone. Still had her feathers and legs. I didn't see him pick her up but I would estimate her to be 150 to 200 foot from the coop on the other side of the fence. This is closer to the wooded area. We swept the back field but I called my lab back after we hit the woods. Didn't find any sign of my two remaining missing birds (two 11 week old Appenzeller Spitzhaubens). I set a live trap next to the coop with a dead chick for bait but nothing had triggered the trap by morning. Not surprising since I walked all the surrounding area with a dog. I will set it again tonight with live chickens next to it protected by a dog kennel covered with 1/2 inch wire mesh. But what could this be? I'm in central KY and we have bobcats, mink, skunks, racoons, oppossum, feral cats, foxes, coyotes, owl and it's possible that I missed a predator so feel free to add!